Enum ColumnOp

pub enum ColumnOp {
    Col(ColId),
    Val(AlgebraicValue),
    ColCmpVal {
        lhs: ColId,
        cmp: OpCmp,
        rhs: AlgebraicValue,
    },
    Cmp {
        lhs: Box<ColumnOp>,
        cmp: OpCmp,
        rhs: Box<ColumnOp>,
    },
    Log {
        op: OpLogic,
        operands: Box<[ColumnOp]>,
    },
}

Variants

Col(ColId)

The value is the the column at to_index(col) in the row, i.e., row.read_column(to_index(col)).

Val(AlgebraicValue)

The value is the embedded value.

ColCmpVal

The value is eval_cmp(cmp, row.read_column(to_index(lhs)), rhs). This is an optimized version of Cmp, avoiding one depth of nesting.

Fields

lhs: ColId

cmp: OpCmp

rhs: AlgebraicValue

Cmp

The value is eval_cmp(cmp, eval(row, lhs), eval(row, rhs)).

Fields

lhs: Box<ColumnOp>

cmp: OpCmp

rhs: Box<ColumnOp>

Log

Let conds = eval(row, operands_i). For op = OpLogic::And, the value is all(conds). For op = OpLogic::Or, the value is any(conds).

Fields

op: OpLogic

operands: Box<[ColumnOp]>

Implementations

impl ColumnOp

pub fn new(op: OpQuery, lhs: Self, rhs: Self) -> Self

pub fn cmp( col: impl Into<ColId>, cmp: OpCmp, val: impl Into<AlgebraicValue>, ) -> Self

pub fn eval_bool(&self, row: &RelValue<'_>) -> bool

Evaluate self to a bool where ColIds are translated to values by indexing into row.

Trait Implementations

impl Clone for ColumnOp

fn clone(&self) -> ColumnOp

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ColumnOp

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for ColumnOp

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl From<AlgebraicValue> for ColumnOp

fn from(original: AlgebraicValue) -> ColumnOp

Converts to this type from the input type.

impl From<ColExpr> for ColumnOp

fn from(ce: ColExpr) -> Self

Converts to this type from the input type.

impl From<ColId> for ColumnOp

fn from(original: ColId) -> ColumnOp

Converts to this type from the input type.

impl From<ColumnOp> for Query

fn from(original: ColumnOp) -> Query

Converts to this type from the input type.

impl Hash for ColumnOp

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for ColumnOp

fn cmp(&self, other: &ColumnOp) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for ColumnOp

fn eq(&self, other: &ColumnOp) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for ColumnOp

fn partial_cmp(&self, other: &ColumnOp) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Eq for ColumnOp

impl StructuralPartialEq for ColumnOp